Elevator system

ABSTRACT

An elevator system is provided to operate between two levels which are capable of relative movement with respect to each other.

[451 Sept. 26, 1972 919,721 4/1909 Hegedus......................187/67 [54] ELEVATOR SYSTEM [72] Inventor: Thomas F. Fitzgibbon, Madison,

Primary Examiner-Evon C. Blunk Assistant ExaminerMerle F. Maffei [73] Assignee: The Garrett Corporation, Los Angeles, Calif.

Attorney-Albert J. Miller and John N. Hazelwood [22] Filed: Aug. 28, 1970 mm ee mm 6V 0 m e aw Wm e or f T C E Am R T mp S e B h A s t i mah e c in mm rwt o c he ew Re ll-r v n wm [Atw 08-0 22%8 I m lm 1 1 7 %B6 7 1 00 3 ,W 7" 6" WM 8" Jm 7 mmm 1 mm 8, mmh m unm mma u e 0 m8 N 1 C m .00 .1 0. Mb H T H M 2 5: 5

4 Claims, 7 Drawing Figures [56] References Cited UNITED STATES PATENTS 849,610 4/1907 Hal1stein......................187/73 ELEVATOR SYSTEM BACKGROUND OF THE INVENTION With the advent of larger bodied commercial aircraft such as the Boeing 747, the aircraft fuselage has been divided into an upper level and a lower level. Transportation for individuals, food, and other items is required between these two levels.

In view of the high altitudes at which these aircraft fly, up to 30,000 ft., pressurization of the aircraft cabin is required. The upper level and lower level are therefore not positioned exactly the same with respect to each other at all times. That is, there may be up to several inches difference between the relative position of the two levels when the cabin is unpressurized and when it is pressurized.

If an elevator is to be used for transportation between these two levels, accurate, positive, repeatable positioning is required for satisfactory operation. Present elevator systems are incapable of meeting these requirements.

SUMMARY or THE INVENTION The invention is directed to an elevator system which provides accurate, positive and repeatable deceleration and stopping between two levels, one of which being movable with respect to the other. During deceleration, the linear motion of the elevator drive chain is converted to harmonic motion.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view, partially cut away, of the elevator system of the present invention.

FIG. 2 is a sectional view of the elevator system of FIG. 1' taken along line 2-2, illustrating the elevator approaching the lower level.

FIG. 3 is a view of the elevator system of FIG. 2 illustrating the elevator positioned at the lower level.

FIG. 4 is a partial view of the elevator system of FIG. 1 illustrating the elevator drive at its top position.

FIG. 5 is a side sectional view of an alternate elevator system of the present invention illustrating the elevator approaching the lower level.

FIG. 6 is a view of the elevator system of FIG. 5 illustrating the elevator at the lower level.

FIG. 7 is a partial plan view of the elevator system of FIG. 5 illustrating the elevator at the upper level.

DESCRIPTION OF THE PREFERRED EMBODIMENTS As illustrated in FIGS. 1, 2, 3, and 4 the elevator system of the present invention comprises an elevator carriage 10 which is carried in a vertical direction by a chain 12. The chain 12 extends between an upper drive sprocket l4 and a lower idler sprocket 16. The drive sprocket 14 is mounted at the top of the elevator support column 18 upon a platform 20. The drive motor 22 for the drive sprocket 14 is also mounted on the platform 20. The idler sprocket I6 is mounted by means of brackets 26 on a lower platform 24 at the lower end of the elevator column 18. While two chain units are illustrated in FIG. 2 only one may be required.

The elevator support column 18 is affixed to the upper floor level. The lower level can move up 2.0 inches or down 0.75 inches from its normal position with respect to the upper level. An upper proximity switch 21 and lower proximity switch 23 are mounted on the column 18 to be operated by a magnet 25 on the back side of chain 12. While the switches 21, 23 will stop the drive motor 22, the linear velocity character of the chain drive is converted to harmonic motion to decelerate and accurately stop the elevator carriage at both the upper and lower levels. This is accomplished by means of linkage 29 inserted in the drive chain 12. The linkage 29, which includes an elongated, partially slotted link 32 positioned in the drive chain 12 can be accommodated in the chain 12 by placing the sprockets l4 and 16 farther apart than the carriage travel. One end of link 36 is slidable in the slot 34 of the elongated slotted link 32. The other end of the link 36 is pivotably connected to one end of a right angle bell crank 38. The elevator carriage is fixed to and moves with the pivot point 40 of the bell crank 38. The other end of the bell crank 38 is pivotably affixed to a lever 42 whose other end is pivotably mounted on an elongated vertical strut or feeler '44 extending downward therefrom. An idler link 46 may join the two ends of the right angle bell crank 38.

As the elevator carriage 10 descends with the linkage 29, the magnet 25 will activate the proximity switch 21 to stop the drive motor. At a prescribed distance above the lower level, regardless of its relative position with respect to the upper level, the vertical strut 44 of the linkage 29 will contact the recess portion 31 of the lower level 30 as shown in FIG. 2. Once the vertical strut 44 contacts the recess 31 in the lower level 30, the bell crank 38, pivotably mounted on the elevator carriage 10, will rotate counterclockwise to harmonically decelerate the elevator carriage and stop it at the lower level 30.

The vertical velocity of the elevator carriage will not diminish until the descending carriage 10 brings the vertical strut 44 into contact with the recess 31 of the lower level 30 and the velocity will reach zero as the bottom of the car contacts bearing blocks 50. The slot 34 in the link'32 permits the chain motion to continue well beyond the lowest possible floor position such that vertical motion of the floor and carriage are accommodated by the slotted link and the drive is unaware of the perambulation. The slot also provides for motion of the lower level when the elevator carriage is locked thereto.

Since the drive structure is fixed with respect to the upper level, the means of decelerating and positioning the carriage at the upper level are much simplified. As shown in FIG. 4, the upper end of the elevator carriage 10 is mounted to the lower ends of a pair of identical links 52, 54 having a pin 56 extending through the slot 34 in the link 32. The other end of the links 52 and 54 are fixed to one of the individual links in the chain 12. As the carriage 10 proceeds upward toward the upper level, the magnet will actuate proximity switch 23 to stop the drive motor 22. The upper end of the links 52 and 54 will proceed up and over the center of the drive sprocket 14. Since these links are vertically restrained by the chain only at their upper end, that is, the links are attached to the car carriage at the lower end and the chain at the upper end, the deceleration at the upper level will be essentially harmonic. A structural stop 55 may be provided for the links 52 and 54 when 3 they are slightly over center on the sprocket 14. In this slightly over center position, the weight of the carriage is carried by the links 52 and 54 to the sprocket l4 and stop and is not borne by the chain 12. Also, the elevator, before starting down, must move a short distance up. The slot 34 in the slot link 32 permits the vertical velocity of the drive chain to be greater than the vertical velocity of the linkage 29 and carriage 10. The

chain 12 does not change length or tension during deceleration and/or stopping at either the upper or lower levels.

It should be noted that considerable variation of drive motor switch cut-off can be tolerated with no effect on the stopping position of the car. Stopping accuracy is not a function of switch performance but is mechanical and positive.

An alternate embodiment of the elevator system of the present invention is illustrated in FIGS. 5, 6, and 7. This alternatesy'stem is quite similar to thatdescribed in'FIGS. 1 through 4 except that the deceleration linkage is somewhat different. The drive chain 62 extends downward from the drive sprocket (not shown) to the elongated slotted link 64. Extending between the top of the slotted link 64'and an upper chain link is a pair of links 66 which are used for the deceleration and positioning at the upper level, much the same as links 52 and 54 in, the previous embodiment. The stop 67 is however mounted to the column 72 rather than the drive sprocket.

A band or cable 68 extends from the bottom end of the slotted link 64, around the idle pulley 70, to the other end of the drive chain 62. The idle pulley is mounted to the column 72 by brackets 74 and 76. A deceleration .cam 78 is mounted on a feeler 80 which extends to recess 82 in the lower level 84. A compression link 86 havingone end in the slot 65 in the slotted link 64 has a cam roller 88 at its other end. A tension link 90 extends between the slot 65 and the cam end of the compression link 86.

As the chain 62 is moved within the column 72, the knee 87 of compression link 86 rides upon wall 73 of the column 72 in the folded position as shown in FIG. 5. Near the lower level, the cam roller 88 on the compression link 86 will contact the deceleration cam 78 which is positioned relative to the lower lever recess 82 by means of the feeler 80. The cam roller 88 will follow the deceleration cam 78 to the position shown in FIG. 6 thereby extending the tension link 90v and unfolding the linkage. The upper end of the compression link is attached to the elevator carriage and carries the weight of the carriage. Except at the lower travel extreme, all of the links are folded up one on the other and thus can be moved up and. down in the restricted space in the column 72. An opening 75 is provided in wall 73 to provide for this unfolding near the lower level.

The basic difference with respect to this alternate elevator system is that the feeler 80, which supports the cam 78, is maintained at the lower leveLand moves continuously with respect to the lower level, whereas in the system described in FIG. 1-4,. the vertical strut 44, which feels the position of the lower level for the bell crank linkage, moves up and down with the linkage.

While specific embodiments of the invention have been illustrated and described, it is to be understood that these embodiments are provided by way of exampie only and that the invention is not to be construed as being limited thereto, but only by the proper scope of the following claims.

What I claim is:

1. An elevator system for operation between two relatively movable levels comprising:

elevator support means extending between said two levels and fixedly secured to the upper of said two levels;

an elevator carriage for movement between said two levels; and

chain drive means mounted upon said elevator support means and including a drive chain having harmonic deceleration linkage, said linkage including a partially slotted link in said drive chain, a first link having a lower end pivotably slidable in the slot in the slotted link and an upper end pivotably secured to the chain above the slotted link, a second link having an upper end pivotably slidable in theslot in the slotted link below the lower end of said first link, a bell crank pivotably mounted upon the elevator carriage having one end pivotably secured to the lower end of said second link, a lower level feeler extending along said drive chain, and a lever arm having one end pivotably mounted to the other end of said bell crank and the other end pivotably mounted to said'lower level feeler.

2. An elevator system for operation between two relatively movable levels comprising:

elevator support means extending between said two levels and fixedly secured to the upper of said two levels;

chain drive means mounted upon said elevator support means and including a drive chain having harmonic deceleration linkage, said linkage including a partially slotted link in said drive chain, a compression link having an upper end pivotably slidable in the slot of the slotted link and a lower end having a roller rotatably mounted thereon, a tension link having one end pivotably mounted on said compression link and another end pivotably slidable in the slot of the slotted link, deceleration cam means slidably mounted at the lower end of said elevator support means and having a deceleration cam located with respect to the position of the lower level for contacting the roller of said compression link, a link having a lower end pivotably attached to the upper end of said slotted link and a claw-like upper end, and a linkage support mounted at the upper end of said elevator support for contact with the claw-like upper end of said link; and

an elevator carriage for movement between said two levels mounted to the upper end of said compression link.

3. An elevator system comprising:

an upper elevator floor level;

a lower elevator floor level disposed beneath said upper elevator floor level and relatively movable with respect thereto;

elevator support means fixedly secured to said upper elevator floor level and extending down to the lower elevator floor level;

chain drive means mounted upon said elevator support means to extend from said upper elevator elevator floor level and extending down to the lower elevator floor level;

chain drive means mounted upon said elevator support means to extend from said upper elevator floor level to said lower elevator floor level, said chain drive means including, a harmonic deceleraan elevator carriage mounted upon the'pivoting bell crank mechanism of said chain drive means to move between said upper elevator floor level and said lower elevator floor level; 10

said pivoting bell crank mechanism of said harmonic deceleration linkage activated when said lower elevator floor level location sensing means contacts the lower elevator floor level to decelerate and accurately stop said elevator carriage at the lower elevator floor level regardless of its relative position with respect to the upper elevator floor tion linkage having a cam positioned on a lower elevator floor level location sensing means which moves in unity with the lower elevator floor level to maintain said cam a constant distance above the lower elevator floor level, and a cam follower mechanism; and

an elevator carriage mounted upon the cam follower mechanism of said chain drive means to move between said upper elevator floor level and said lower elevator floor level;

said cam follower mechanism of said harmonic level. 2:: i:zzzrznrriiaaisr at 8211 11:13:22,; an upper elevator floor level; e y p riage at the lower elevator floor level regardless of its relative position with respect to the upper elevator floor level.

a lower elevator floor level disposed beneath said upper elevator floor level and relatively movable with respect thereto;

elevator support means fixedly secured to said upper 

1. An elevator system for operation between two relatively movable levels comprising: elevator support means extending between said two levels and fixedly secured to the upper of said two levels; an elevator carriage for movement between said two levels; and chain drive means mounted upon said elevator support means and including a drive chain having harmonic deceleration linkage, said linkage including a partially slotted link in said drive chain, a first link having a lower end pivotably slidable in the slot in the slotted link and an upper end pivotably secured to the chain above the slotted link, a second link having an upper end pivotably slidable in the slot in the slotted link below the lower end of said first link, a bell crank pivotably mounted upon the elevator carriage having one end pivotably secured to the lower end of said second link, a lower level feeler extending along said drive chain, and a lever arm having one end pivotably mounted to the other end of said bell crank and the other end pivotably mounted to said lower level feeler.
 2. An elevator system for operation between two relatively movable levels comprising: elevator support means extending between said two levels and fixedly secured to the upper of said two levels; chain drive means mounted upon said elevator support means and including a drive chain having hArmonic deceleration linkage, said linkage including a partially slotted link in said drive chain, a compression link having an upper end pivotably slidable in the slot of the slotted link and a lower end having a roller rotatably mounted thereon, a tension link having one end pivotably mounted on said compression link and another end pivotably slidable in the slot of the slotted link, deceleration cam means slidably mounted at the lower end of said elevator support means and having a deceleration cam located with respect to the position of the lower level for contacting the roller of said compression link, a link having a lower end pivotably attached to the upper end of said slotted link and a claw-like upper end, and a linkage support mounted at the upper end of said elevator support for contact with the claw-like upper end of said link; and an elevator carriage for movement between said two levels mounted to the upper end of said compression link.
 3. An elevator system comprising: an upper elevator floor level; a lower elevator floor level disposed beneath said upper elevator floor level and relatively movable with respect thereto; elevator support means fixedly secured to said upper elevator floor level and extending down to the lower elevator floor level; chain drive means mounted upon said elevator support means to extend from said upper elevator floor level to said lower elevator floor level, said chain drive means including harmonic deceleration linkage having a pivoting bell crank mechanism and a lower elevator floor level location sensing means movable with said pivoting bell crank mechanism; and an elevator carriage mounted upon the pivoting bell crank mechanism of said chain drive means to move between said upper elevator floor level and said lower elevator floor level; said pivoting bell crank mechanism of said harmonic deceleration linkage activated when said lower elevator floor level location sensing means contacts the lower elevator floor level to decelerate and accurately stop said elevator carriage at the lower elevator floor level regardless of its relative position with respect to the upper elevator floor level.
 4. An elevator system comprising: an upper elevator floor level; a lower elevator floor level disposed beneath said upper elevator floor level and relatively movable with respect thereto; elevator support means fixedly secured to said upper elevator floor level and extending down to the lower elevator floor level; chain drive means mounted upon said elevator support means to extend from said upper elevator floor level to said lower elevator floor level, said chain drive means including, a harmonic deceleration linkage having a cam positioned on a lower elevator floor level location sensing means which moves in unity with the lower elevator floor level to maintain said cam a constant distance above the lower elevator floor level, and a cam follower mechanism; and an elevator carriage mounted upon the cam follower mechanism of said chain drive means to move between said upper elevator floor level and said lower elevator floor level; said cam follower mechanism of said harmonic deceleration linkage activated by said cam to decelerate and accurately stop said elevator carriage at the lower elevator floor level regardless of its relative position with respect to the upper elevator floor level. 